Apparatus for providing gaseous sample ions/molecules and a corresponding method

Abstract

An apparatus for providing gaseous sample ions/molecules from liquid droplets containing sample ions/molecules. The apparatus has a chamber having one or more walls which define an interior of the chamber, the chamber being configured to receive liquid droplets containing sample ions/molecules. The apparatus also has a gas flow producing means configured to produce a flow of gas within the chamber for promoting evaporation of liquid droplets in the chamber to provide gaseous sample ions/molecules. The apparatus is configured such that the flow of gas produced within the chamber inhibits liquid droplets in the chamber from coming into contact with the one or more walls of the chamber.

1 . An apparatus for providing gaseous sample ions/molecules from liquid droplets containing sample ions/molecules, the apparatus having:
 a chamber having one or more walls which define an interior of the chamber, the chamber being configured to receive liquid droplets containing sample ions/molecules;   a gas flow producing means configured to produce a flow of gas within the chamber for promoting evaporation of liquid droplets in the chamber to provide gaseous sample ions/molecules;   wherein the apparatus is configured such that the flow of gas produced within the chamber inhibits liquid droplets in the chamber from coming into contact with the one or more walls of the chamber.   
     
     
         2 . An apparatus according to  claim 1 , wherein the apparatus is configured such that the flow of gas produced within the chamber has a vortex or swirling structure in at least a region of space within the chamber. 
     
     
         3 . An apparatus according to  claim 1  wherein the flow of gas within the chamber has an inner region and an outer region in which the flow of gas has an axial velocity in a forward direction, as well as an intermediate region, between the inner region and outer region, in which the flow of gas has an axial velocity in a reverse direction that is opposite to the forward direction. 
     
     
         4 . An apparatus according to  claim 1 , wherein the apparatus evaporates substantially all the liquid droplets received by the chamber. 
     
     
         5 . An apparatus according to  claim 1 , wherein the chamber includes a sample outlet and the apparatus includes one or more electrodes configured to produce an electric field within the chamber to direct gaseous sample ions towards the sample outlet so that the gaseous sample ions exit the chamber via the sample outlet. 
     
     
         6 . An apparatus according to  claim 5 , wherein the electrodes are configured so that the electric field is substantially orthogonal to the flow of gas in at least a region of space within the chamber. 
     
     
         7 . An apparatus according to  claim 1 , wherein the one or more walls of the chamber which define the interior of the chamber include a wall selected from a cylindrical wall, a toroidal wall, a conical wall, a spiral wall, or a helical wall. 
     
     
         8 . An apparatus according to  claim 1 , wherein at least a portion of a wall of the chamber is configured to rotate about an axis of the chamber. 
     
     
         9 . An apparatus according to  claim 8 , wherein the at least a portion of a wall is configured to rotate around an axis of the chamber as a consequence of the gas flowing out from the chamber. 
     
     
         10 . An apparatus according to  claim 8 , wherein the at least a portion of a wall is configured to rotate around an axis of the chamber with the assistance of an external energy source. 
     
     
         11 . An apparatus according to  claim 1 , wherein the apparatus includes an energy input device configured to promote evaporation of the liquid droplets by supplying energy to the liquid droplets. 
     
     
         12 . An apparatus according to  claim 11 , wherein the energy input device includes one or more devices selected from:
 a heating device for heating gas which passes into the chamber via the gas inlet;   a heating device for heating the chamber;   a source of microwaves for supplying microwaves to the chamber; and/or   an acoustic device for supplying acoustic vibrations to the chamber.   
     
     
         13 . An apparatus according to  claim 1 , wherein the apparatus is configured to regulate the flow of gas within the chamber in response to one or more sensors located at an outlet of the chamber. 
     
     
         14 . An apparatus according to  claim 1 , wherein the apparatus includes a source of liquid droplets configured to produce liquid droplets containing sample ions/molecules to be received by the chamber. 
     
     
         15 . An apparatus according to  claim 14 , wherein the source of liquid droplets includes any one of the following:
 an electrospray ionisation source;   an atmospheric pressure chemical ionisation source;   an atmospheric pressure photoionisation source;   a desorption electrospray ionisation source;   an atmospheric pressure matrix-assisted laser desorption/ionisation source;   a thermospray ionisation source;   a source configured to use electro-flow focussing.   
     
     
         16 . An apparatus according to  claim 1 , wherein the apparatus includes at least one additional chamber configured to receive gaseous sample ions/molecules from the chamber via a sample outlet in the chamber, the additional chamber being configured to have a pressure that is lower than that of the chamber. 
     
     
         17 . An apparatus according to  claim 1 , wherein the apparatus is included in a mass spectrometer which also has a mass analyser configured to analyse gaseous sample ions from the chamber. 
     
     
         18 . An apparatus according to  claim 17 , wherein the mass analyser includes any one of the following:
 a quadrupole mass filter;   a triple quadrupole mass spectrometer;   an ion cyclotron resonance mass analyser;   a time of flight mass analyser;   one or more RF ions traps;   one or more electrostatic ion traps;   hybrid variants of the above.   
     
     
         19 . An apparatus for providing gaseous sample ions/molecules from liquid droplets containing sample ions/molecules, the apparatus having:
 a chamber having one or more walls which define an interior of the chamber, the chamber being configured to receive liquid droplets containing sample ions/molecules;   wherein the apparatus is configured such that a flow of gas produced within the chamber inhibits liquid droplets in the chamber from coming into contact with the one or more walls of the chamber.   
     
     
         20 . A method of providing gaseous sample ions/molecules from liquid droplets containing sample ions/molecules, the method including:
 receiving liquid droplets containing sample ions/molecules in a chamber having one or more walls which define an interior of the chamber;   producing a flow of gas within the chamber for promoting evaporation of liquid droplets in the chamber to provide gaseous sample ions/molecules;   wherein the flow of gas produced within the chamber inhibits liquid droplets in the chamber from coming into contact with the one or more walls of the chamber.